Polymer Flash Corridor Ammunition

ABSTRACT

The present invention relates to firearm ammunition incorporating a flash corridor and converting conventional ammunition into flash corridor ammunition. Case section couples to base section with flash corridor insert disposed within base section. Case locking coupler fits within base locking cavity and base locking coupler fits within case locking cavity. Flash corridor insert is kept in place by friction between case section and base section.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to U.S. Provisional Patent Application Ser. No. 62/679,123, filed Jun. 1, 2018, entitled “Polymer Flash Corridor,” the disclosure of which is expressly incorporated by reference herein.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

The invention described herein was made in the performance of official duties by employees of the Department of the Navy and may be manufactured, used and licensed by or for the United States Government for any governmental purpose without payment of any royalties thereon. This invention (Navy Case 200,537) is assigned to the United States Government and is available for licensing for commercial purposes. Licensing and technical inquiries may be directed to the Technology Transfer Office, Naval Surface Warfare Center Crane, email: Cran_CTO@navy.mil.

FIELD OF THE INVENTION

The present invention relates to firearm ammunition incorporating a flash corridor.

BACKGROUND AND SUMMARY OF THE INVENTION

The present invention relates to firearm ammunition incorporating a flash corridor and converting conventional ammunition into flash corridor ammunition. In conventional ammunition, a firing pin ignites the primer, and the primer ignites the propellant. The propellant then burns from the primer to the projectile. This “one-directional” burning causes propellant to be discharged through the case throat and into the firearm barrel.

According to an illustrative embodiment of the present disclosure, ammunition can be converted into flash corridor ammunition by adding a flash corridor insert into a case. Igniting a primer causes molten material to travel down the flash corridor to the propellant bed midway up the cartridge. The reaction then moves away from the initial reaction point in both directions, toward the rear and front of the cartridge. The retained propellant in the rear of the cartridge reacts within the cartridge so that less reacting propellant enters the barrel. Flash corridor inserts allow existing ammunition to be quickly and cheaply repurposed while also improving performance over the original ammunition. A variety of insert shapes can be used, facilitating the use of alternative propellants and unconventional cartridge designs. While flash corridor inserts can be made of many materials (e.g., metals), polymer inserts are cheap and easy to manufacture.

According to a further illustrative embodiment of the present disclosure, a flash corridor is incorporated into injection molded polymer cased ammunition to create polymer cases with built-in flash corridors. Because the cost change beyond tooling is negligible, existing injection molded polymer systems can be used at minimal cost.

Additional features and advantages of the present invention will become apparent to those skilled in the art upon consideration of the following detailed description of the illustrative embodiment exemplifying the best mode of carrying out the invention as presently perceived.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description of the drawings particularly refers to the accompanying figures in which:

FIG. 1 shows an assembled cartridge with a shaped flash corridor.

FIG. 2 shows a case with a flash corridor insert.

FIG. 3 shows a case with a flash corridor insert.

FIG. 4 shows a case with an integrated flash corridor.

DETAILED DESCRIPTION OF THE DRAWINGS

The embodiments of the invention described herein are not intended to be exhaustive or to limit the invention to precise forms disclosed. Rather, the embodiments selected for description have been chosen to enable one skilled in the art to practice the invention.

FIG. 1 shows an assembled cartridge 1 with a shaped flash corridor insert 7. A projectile 3 is coupled to case 5. When primer 8 is ignited, molten material travels through flash corridor 13 until it contacts and ignites propellant 9. The propellant then burns away from the initial reaction point in both directions, toward the rear and front of the cartridge. This bi-directional burn causes smoother and more consistent burn and lower chamber pressures.

FIG. 2 shows a case with a flash corridor insert 7. Case section 15 couples to base section 21 with flash corridor insert 7 disposed within base section 21. Case locking coupler 19 fits within base locking cavity 25 and base locking coupler 23 fits within case locking cavity 17. Flash corridor insert 7 is kept in place by friction between case section 15 and base section 21. In exemplary embodiments, flash corridor insert 7 can be used to convert existing ammunition into flash corridor ammunition.

FIG. 3 shows a case with a flash corridor insert 7. Case section 15 couples to flash corridor insert 7 and flash corridor insert 7 couples to base section 21. Case locking coupler 19 fits within insert locking cavity 35, base locking coupler 23 fits within insert locking cavity 35, first insert locking coupler 31 fits within case locking cavity 17, and second insert locking coupler 33 fits within base locking cavity 25. In exemplary embodiments, case section 15 and base section 21 are formed to incorporate flash corridor insert 7. By utilizing standardized couplers 19, 23, 31, 33 and cavities 17, 25, 35, flash corridor insert 7 can be replaced with alternative flash corridor inserts.

FIG. 4 shows a case with an integrated flash corridor section. Case section 15 couples to base section 21 with flash corridor insert 7 disposed within base section 21. Case section 15 is formed with a flash corridor 13. Case locking coupler 19 fits within base locking cavity 25 and base locking coupler 23 fits within case locking cavity 17. In exemplary embodiments, flash corridor 13 is formed within case section 15 at the time of manufacturing. Injection molded polymer cases can be manufactured to include a flash corridor by modifying the injection mold.

An exemplary method of modifying ammunition comprises providing conventional case and base sections, disposing a flash corridor insert within the base section such that the flash corridor insert connects to a primer with the base section, and coupling the case section to the base section.

Although the invention has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the spirit and scope of the invention as described and defined in the following claims. 

1. A firearm cartridge comprising: a case section; a base section comprising a primer; a flash corridor insert comprising a flash corridor; wherein the flash corridor insert is disposed within the base section such that the primer is coupled to the flash corridor; wherein the case section is coupled to the base section, wherein the flash corridor insert is held in place by friction between the case section and the base section.
 2. A firearm cartridge comprising: a case section; a base section comprising a primer; a flash corridor insert comprising a flash corridor; wherein the flash corridor insert is disposed within the base section such that the primer is coupled to the flash corridor; wherein the case section is coupled to the flash corridor insert and the flash corridor insert is coupled to the base section.
 3. A firearm cartridge comprising: a case section comprising a flash corridor; a base section comprising a primer; wherein the case section is coupled to the base section such that the primer is coupled to the flash corridor. 